Question

A die has two faces each with number ‘1’, three faces each with number ‘2’ and one face with number ‘3’. If die is rolled once, determine
(i) P (2) (ii) P (1 or 3) (iii) P (not 3)

Answer 1

Total number of faces = 6
(i) Number faces with number ‘2’ = 3
$∴P(2)=\frac{3}{6}=\frac{1}{2}$

(ii) P (1 or 3) = P (not 2) $= 1 - P (2)=1-\frac{1}{2}=\frac{1}{2}$

(iii) Number of faces with number ‘3’ = 1
$∴P(3)=\frac{1}{6}$
Thus P(not 3)=$1-P(3)=1-\frac{1}{6}=\frac{5}{6}.$